Tapered can body blank



Jan. 27, 197-0 T. E. JO'HNSON 3,491,635

TAPERED CAN BODY BLANK Filed June 15. 1967 5 Sheets-Sheet l INVENTOR.

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TAPERED CAN BODY BLANK Filed June 15. 19676 5 Sheets-Sheet 2 D INVENTOR.

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TAPERED CAN BODY BLANK Filed June 15, 1967 5 Sheets-Sheet 5 INVENTOR.

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TAPERED CAN BODY BLANK Filed June 15. 1967 5 Sheets-Sheet 4 INVENTOR.

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mm 5. MAWSO/V Jan. 27., 1970 T. E. JOHNSON TAPERED CAN BODY BLANK 5 Sheets-Sheet 5 Filed June 15, 1967 I .H v "Hul a mm INVENTOR. B M01? 5. JU/M M/V United States Patent 3,491,635 TAPERED CAN BODY BLANK Thor E. Johnson, San Francisco, Calif., assignor to M.J.B. Company, a corporation of Delaware Filed June 15, 1967, Ser. No. 646,380 Int. Cl. B26d 3/00 US. C]. 83-43 1 Claim ABSTRACT OF THE DISCLOSURE A method is provided for producing a tapered can body blank by making a series of cuts in a blank as it is intermittently fed through a scroll shear.

BACKGROUND OF THE INVENTION Field of the invention Manufacture of body blanks used in making tapered cans.

Description of prior art Heretofore blanks for can bodies have been made with punch-press operations. A punch-press for cans of large size is an expensive and heavy piece of machinery and requires expensive dies. In accordance with the present invention a scroll shear press is used with progressive dies to form the can body. This results in a much less expensive operation particularly when one is making large size cans in relatively small quantity. Another advantage of the present invention is that it gets rid of waste more efficiently since the punching skeleton is left on the table of a punch-press while in the present operation, the stock from which the body is made and the finished blank move in a straight line across the machine, while the waste is broken up and removed at a lower level. Further, the method of the present invention provides an accurate indexing method wherein all locations of the punching operation are taken from the same point on the blank, resulting in an accurate blank. In accordance with the prior art, location is done off a portion of the waste skeleton resulting in less accuracy.

SUMMARY OF THE INVENTION A scroll shear is used to form a tapered blank for making a can body in a series of progressive operations. A novel method is also provided of manufacturing a die to accommodate the different radii at the bottom and the top of the can blank.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side view of a scroll shear used in forming a body blank of the present invention.

FIGURE 2 is a view of cut-out blanks showing the relationship to the stock from which the blank is made.

FIGURE 3 is a finished can body made from a blank produced in accordance with the present invention.

FIGURE 4 is a diagrammatic view of the successive stages in forming a can body blank.

FIGURE 5 is a plan view of the die profile which is used for producing the can body blank.

FIGURE 6 is an enlarged plan view at two different levels showing the scroll shear employed in performing the process of the present invention.

FIGURE 7 is a section on the line 7-7 of FIGURE 6.

FIGURE 8 is a section on the line 88 of FIGURE 6.

FIGURE 9 is a view on the line 9-9 of FIGURE 8.

FIGURE 10 is a diagrammatic view showing the method of forming a die used in forming the present invention.

FIGURE 11 is a partial end View of a scroll shear used in performing the process of the present invention.

FIGURE 12 is a section on the line 12--12 of FIG- URE 11.

FIGURE 13 is an enlarged partial view of the locator portion of the device.

FIGURE 14 is a section on the line 14-14 of FIG URE 12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGURE 1, a side view of a scroll shear is shown in simplified form. The scroll shear includes a frame member generally designated 14 having a reciprocating ram generally designated 16 which is driven from an eccentric 18. A second eccentric 20 actuates a feeding device 22 to feed the sheet stock from which the body blank is made in timed relationship with the action of the ram 16. Further, through a common drive shaft, endless chains 24, 26 and 28 actuate drive mechanisms as is disclosed in detail later.

In FIGURES 6 through 14 are various details of the scroll shear and particularly the dies used therein, are brought out. Since the scroll shear itself is a piece of equipment Well known to those skilled in the art, all of the details of operation are not given, but only those details are given which are particularly pertinent to the present invention. The ram previously generally designated 16, is reciprocated on two guides, '28 and 30 and carries on it an upper die generally designated 32 which can be made in one or more parts and which essentially has a front cutting edge 34, a rear cutting edge 36, side cutting edges 38 and 40 and notching sections 42 and 44. These parts move against a lower stationary mating die generally designated 46. Shafts 48 and 50 are driven in timed relationship, as previously described, and are provided with rollers, having partial resilient coverings 52 and 54 thereon, for moving the stock through the die between cutting operations. Mounted between the shafts 48 and 50 are the magnet members 53 which support the stock against the locators 61 during and after the cutting operation and pusher means 55 operated by shaft 56 which is actuated by cam 58 on shaft 48, serve to dislodge the finished blanks from the magnets so that they can be pulled forward and stacked by rollers 52 and 54.

In FIGURE 4, there is shown the sequence of operations by which the can body blank is made" from the sheet stock. In the embodiment illustrated, a sheet 60 (see FIGURE 2) will provide two body blanks 64 and 66. If a single sheet were passed through the machine, four strokes of the die would be needed to form the two blanks from the sheet, but since the sheets are ordinarily pushed through in successive order, and the trailing edge of a preceding sheet is cut simultaneously with the leading edge of the succeeding sheet at a single stroke, three strokes are used to form two blanks. Thus the blank 64 is first cut at the position shown in Al where the notches are formed and which locate the sheet for further operation. At BII, the sheet has moved forward approximately one-half its length where the sides and leading edge of the first blank are cut as well as the notches for the second blank. The blank is moved to C111 and in this position the location members 61 fit into the notches cut in the stock, resulting in accurate indexing. At CIII, the trailing edge of the first blank and the leading edge of the second blank have been cut and at DIII, the second blank has advanced so that its trailing edge has been cut. It will be understood that cuts A and D are combined so that as the die is notching one blank, it is simultaneously cutting the trailing edge on a preceding sheet.

As has been previously mentioned, the present invention contemplates making a tapered can so that it is necessary that the top and bottom edges of the blanks not be parallel. Thus, there is shown in diagrammatic form in FIGURE 5, the die having a radius R for cutting the trailing edge of the blank and a radius R for the leading edge of the blank. The radius R is smaller than the radius R". Normally it would be difficult to fabricate such a die, but in FIGURE 10 there is illustrated the method by which the die of the present invention is fabricated. Thus, one starts with a strip 68 of steel die stock and then place it in the jig and bends it to a concave figuration as is shown at 70. Now the surface is ground flat with the material shown in dash lines at 72 being removed. The die is now placed in a frame 74 and bent into a meniscus as is shown at 76, resulting in two cutting surfaces, namely R and R wherein the radius R is greater than the radius R. Thus, in this simple manner it is possible to fabricate a die having these relatively complex curves.

The blank made in accordance with the present invention lends itself to the formation of a tapered can as is shown in FIGURE 3 and which is described in detail on my co-pending application, Ser. No. 614,905 filed Feb. 9, 1967, now Patent No. 3,425,382.

I claim:

1. The method of fabricating a can body blank suitable for use in making the body of a tapered can, comprising cutting said blank on a scroll shear utilizing a plurality of cuts to form the blank in the following sequence:

(a) a sheet of stock is notched for the first body blank,

(b) said sheet is advanced and the leading edge and sides of the first body blank are formed,

(c) the sheet is again advanced and the trailing edge of the first blank and the leading edge of the second blank as well as the sides and notches of the second blank are formed,

(d) the trailing edge of the second blank is cut, and (e) steps (a) and (d) are combined in a single stroke.

References Cited UNITED STATES PATENTS 3/1934 Murch 8352 X 9/1939 Ponndorf et al. 8343 8/1949 Egenolf et a1. 83 32 X 2/1966 Wood 8352 X FOREIGN PATENTS 2/ 1902 Great Britain. 1/1932 Great Britain.

US. Cl. X.R. 

